What is the purpose of a reagent blank in analytical measurements?

The purpose of a reagent blank in analytical measurements is to correct analytical results for baseline interferences. A reagent blank contains all the components of the analytical procedure except the analyte of interest. By measuring the response of the reagent blank, any background signal or interference contributed by the reagents themselves can be identified and subtracted from the results of actual samples. This ensures that the measurements reflect the true concentration of the analyte, without the confounding effects of background noise or impurities from the reagents used.

This adjustment is crucial for achieving accuracy in quantitative analyses, as it helps to calibrate the instrument and the analytical method to distinguish between the actual analyte signal and other interference components. Therefore, using a reagent blank is an essential practice in improving the reliability of analytical results.